Two Useful Guides To Software Alternatives

alternativeTo

alternativeTo provides lists of software that can replace your existing software with open source and free alternatives. This well-organized site allows people to vote on the software choices.

Prism Break

Prism Break provides a well-researched list of software that can increase your security, and help you opt out of surveillance. This list tends to be technical, but there are many useful services here that have been reviewed by privacy enthusiasts.